Drink beet juice to help blood flow, lower blood pressure

A glass of beet juice a day may not keep the cardiologist away, but it could give your heart a solid boost. People with high blood pressure who drank a cup of the earthy purple brew lowered their blood pressure for up to 24 hours, according to a small study published today in the journal Hypertension.

"It is well known that eating fruits and vegetables is good for cardiovascular health," said Amrita Ahluwalia, PhD, the lead author of the study and a professor of vascular biology at The Barts and The London Medical School in London. However, vegetables that are rich in compounds call nitrates, including beets and their juice, may offer special benefits for people with elevated blood pressure, she said.

In the body, nitrates from food are converted into nitrites and ultimately nitric oxide. This gas expands blood vessels, which improves blood flow and lowers blood pressure. Nitric oxide has the opposite effect of stress or cold temperatures, which cause blood vessels to constrict, thus raising blood pressure temporarily.

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In the study, 15 adults with stage 1 hypertension -- defined as systolic blood pressure between 140 and 159 millimeters of mercury (mm Hg) -- drank about 8 ounces of beet juice or the same amount of water with a low nitrate content and had their blood pressure monitored for the next 24 hours. A cup of beet juice has roughly the same nitrate content as two whole beets.

The beet drink decreased participants' blood pressure by approximately 10 millimeters of mercury (mm Hg), with the greatest drop occurring 3 to 6 hours after they consumed the juice.

In previous trials, Dr. Ahluwalia and her colleagues found that people with normal blood pressure required twice as much beet juice -- a full pint -- to see the same reduction in blood pressure. "In this study, we saw that a dose that had a really small effect in healthy people had a really impressive effect in people with high blood pressure," she said.

However, the new study demonstrated only the short-term effects of drinking beet juice. Ahluwalia is completing a longer study to see if people with high blood pressure would continue to benefit from drinking a daily glass of beet juice for four weeks.

Ahluwalia said bottled beet juice is readily available in the United Kingdom, where the study was performed. However, here in United States, you'll probably have to make a special trip to a health store or juice bar to get your hands on the drink, said Katherine Patton, RD, a registered dietitian in the Preventive Cardiology Clinic at the Cleveland Clinic.

The good news is, you don't have to sip the juice -- or even eat whole beets -- to rein in your blood pressure. Plants take up nitrates from the soil in order to grow, and many vegetables, especially leafy greens, are good sources, according to Nathan Bryan, PhD, a biochemist at The University of Texas Health Science Center at Houston who studies the health effects of nitric oxide. In fact, "kale has the highest nitrate content of any vegetable we've tested, including beets," he said.

Some studies have raised concerns about a possible link between nitrates and nitrites in processed meat and gastrointestinal cancers, but experts say there is no reason to be alarmed about the nitrates found in vegetables. Nitrates and nitrites, while not carcinogenic on their own, can combine with compounds from proteins in the gut to form nitrosamines, some of which are thought to cause cancer in humans. However, vegetables also contain antioxidants, such as vitamin C, that block the formation of nitrosamines. "Nature has provided a way to generate the benefits of nitric oxide without the risk of forming these nitrosamine compounds," said Bryan.

"There is some evidence of toxicity from the addition of nitrites to processed meats, but there is no evidence of nitrates in vegetables causing these effects," Ahluwalia added. "There is no evidence to suggest that eating vegetables gives you cancer -- in fact, it's quite to the contrary."

To improve heart health, Patton recommends follow the government's MyPlate guidelines and filling at least half of your plate with vegetables and fruits at lunch and dinner. "If you know your diet is low in vegetables, then making an effort to eat more vegetables -- especially as a replacement for high-sodium foods -- could really help lower your blood pressure."